Rotary injection molding apparatus and method for use

ABSTRACT

A rotary injection molding apparatus and method for manufacturing products containing elastomeric material within multi-section single cavity molds. The apparatus includes a modular frame supporting an injection molding operation station having an injector assembly with a pressure sensitive nozzle assembly. The injector assembly is engaged with an extruder assembly at a check valve assembly. A mold servicer assembly is provided for assembly and disassembly of multi-section single cavity molds. A robotic arm assembly is supported on the modular frame and positioned for inserting and removing products or product components from disassembled molds. Finally; a rotating table is provided on the frame which has a plurality of work station positions supporting clamping assemblies for clamping single cavity molds around the periphery of the rotating table.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from U.S. patent applicationSer. No. 60/455,275 filed Mar. 17, 2003, the entire subject matter ofwhich is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to invention molding machines and morespecifically to a rotary injection molding apparatus and method for itsuse.

2. Background of the Related Art

Injection molding machines are commonly used in the manufacturingindustry for molding elastomeric materials such as rubber, plastic orcombinations of these materials. For example, current vibration controlcomponents for the automotive industry are produced using largeinjection press machinery with multi-cavity molds. Multi-cavity moldsproduce large amounts of natural rubber waste from the largerunner-system, cavity flash, and damaged cavities. The time and cost toengineer and manufacture these intricate molds and their associatedtolling is very high. Product quality and consistency is alsocompromised due to the variation in cavity pressures and temperature.

The multi-cavity mold style of molding also requires extensive operatorintervention, which can lead to operator error and operator injuries dueto the hazards associated with the large, heavy, hot molds. Automatinghigh-cavity molds is clumsy, expensive and often unsuccessful. Themulti-cavity systems almost always require secondary finishingoperations, which cost the plant time and money.

Additionally, in prior art multi-cavity mold systems, performing taskssuch as mold changes for different parts required the use of heavylifting equipment. Also, moving the press to another location is noteasily done since many of these large presses require a large floor pit.

Prior examples of injection molding machine solutions which avoid theuse of multi-cavity molds are disclosed in U.S. Pat. Nos. 6,604,936 and5,843,487. The components of prior single mold injection molding systemstypically include a stock supply assembly, an extruder assembly, aninjection assembly, a mold and a clamping assembly. In a typical moldingprocess, the stock supply assembly supplies a certain amount of stockmaterial to the extruder assembly. The extruder assembly processes orplasticizes the stock material into injection material, and conveys thedesired amount of material to the injection assembly. Upon clamping ofthe mold within the clamping assembly under the force necessary forsuccessful molding, the injection assembly injects the injectionmaterial into a mold cavity within the mold. When a metal insert orother mold component is required in the molding procedure using aninjection molding machine, sections or portions of the mold mustinitially be separated and an unfinished component, insert or work pieceloaded into one of the mold sections. The mold sections are thenassembled to form the internal mold cavity.

Once the mold cavity is formed, the mold is clamped under the necessaryforce to hold the unfinished inserts, components or work pieces inposition during operation of the injection assembly, which injects theelastomeric molding material into the mold cavity. The mold sections arethen opened or removed and the molded product having the previouslyunfinished, now molded part and insert or joined work pieces, areunloaded from the mold cavity. However, none of these prior solutionsprovides the advantages of a rotary injection molding system.

SUMMARY OF THE INVENTION

The present invention provides a safe, simple and more efficientinjection molding apparatus and method for injection molding elastomericproducts by using multiple single cavity molds which are rotated intoand out of operation on a rotating table. By using single cavity molds,all the disadvantages of the multi-cavity system method are eliminatedor reduced.

Advantages of the use of single cavity molds over multi-cavity moldsystems include that they have little or no runner system, so naturalwaste is dramatically reduced. Cavity flash can be minimized oreliminated by accurate and precise control of cavity fill pressures andconcentrated clamp forces at the surfaces adjacent to the cavity.Secondary trimming operations for flash removal, or other finishingoperations, may also be eliminated or reduced. Single cavity molds canbe designed and fabricated in a fraction of the time it takes to designand manufacture a multi-cavity mold. Also, changes to the single cavitymolds can be implemented rapidly, leading to shorter product-to-markettime. The smaller mold size also allows for easy mold change capability,as well as easier and less dangerous handling by operators.

While prior single cavity systems of injection molding have been used,the present application provides numerous improvements over such priorsystems. The automated rotary injection apparatus of the presentapplication enables increased efficiency due to the use of an increasednumber of mold stations supporting individual, removable, multi-section,single cavity molds within individual clamping assemblies on a rotatingtable. Easy integration of additional upstream and downstream operationsis also possible, such as the application of a swager into the press.The modularity of the present apparatus enables the assembly of acompleted machine having multiple components or modules in one systemwhich may be readily shipped in a manner which is ready for use rightoff the truck.

The present injection molding apparatus is provided within a modularframe which supports a fixed injection molding operation station whichincludes an extruder assembly, and an injection assembly with a nozzleassembly, which are interconnected at a check valve assembly.Elastomeric stock material is supplied to the extruder assembly by asupply assembly. A mold servicer assembly is provided at a disassemblystation, adjacent the injection molding operation station, where themulti-section single cavity molds are disassembled and reassembled bythe mold servicer assembly prior to engagement with the injectionmolding operation station. A robotic assembly or robot arm is alsosupported on the modular frame. The robotic assembly is preferablyprovided with at least 6 degrees of freedom and is positioned at acorner of the modular frame to permit access to the single cavity moldat the disassembly station as well as to adjacent injection moldingsystems. Finally, the modular frame supports a rotating table having aplurality of stations along its periphery, preferably at least 8 or morestations. Each station supports a clamping assembly for clamping amulti-section single cavity mold therein during operations at theinjection molding operation station and thereafter for curing as themold moves around the rotating table back to the disassembly station. Asused herein, the term “cure” is intended to include treatment by theapplication of heat, pressure, or other material treatments whereby themolding process is completed and the manufactured product containingelastomeric materials and any components attains its finished condition.

To begin the process of manufacturing a product, the mold servicerassembly disassembles the multi-section single cavity mold at thedisassembly station. Inserts or other product components are supplied tothe mold cavity by the robotic arm. Such inserts or components may besupplied to the robotic arm by belt conveyors, bowl or magazine feederspositioned adjacent the rotary injection molding apparatus.Alternatively, an operator may inserts components to be molded prior tothe injection operation.

The mold is then reassembled by the mold servicer assembly and movedinto engagement within a clamping assembly supported on the rotatingtable. The rotating table then moves the mold into the injection moldingoperation station adjacent the extruder and injector assemblies, and apressure sensitive nozzle assembly is then advanced into engagement witha sprue opening in the mold. Once the nozzle assembly engages the mold,elastomeric material previously provided from the extruder assembly tothe injector assembly via the rotary check valve assembly, is thenprovided to the mold again via the rotary check valve. Once the materialis injected into the mold, the rotating table advances the mold toanother position, while another mold within a clamping assembly has alsobeen advanced to the injection molding operation station for the nextsuccessive injection molding operation. Where the rotating table isprovided with 10 stations, additional injection operations are performedsuccessively upon additional molds until the original mold returns tothe original station and is provided to the mold servicer assembly fordisassembly and removal of the manufactured product. The robot assemblyis preferably used to remove the manufactured product, to remove wastematerial from the sprue opening and runner system, as well as to preparethe mold for the next molding operation, by inserting any necessaryproduct components into the mold cavity.

Following removal of manufactured products and preparation of the moldfor the next molding operation, the mold servicer assembly reassemblesthe multi-sections of the single cavity mold, and the process isrepeated as previously described. Manufactured product may be removed toan adjacent belt conveyor to shipping containers, or provided manuallyor via the robot assembly to additional adjacent processing stations,such as a buffing, oil dipping or swaging station.

A control system is provided for automatically controlling operation ofthe rotary injection molding apparatus, such as system and componentpressures, speeds, temperatures, cycle times and injection volumes.

These and other advantages and features of the invention will be betterunderstood from the detailed description of an embodiment of theinvention which is described in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial, schematic perspective view of the rotary injectionmolding apparatus of the present application with safety panels removed;

FIG. 2 is a partial, schematic perspective view of the apparatus of FIG.1 having safety panels in place, and with a supply of product componentsbeing supplied via a belt conveyor;

FIG. 3. is a cut-away partial, schematic view of the apparatus of thepresent invention having safety panels removed, and with optionaladditional stations shown in the form of a belt conveyor supplyingproduct components, a swager unit positioned adjacent the mold servicerassembly, and a take away belt conveyor for removing completed productsfrom the apparatus;

FIGS. 4A and 4 B are cut away partial, schematic views of the injectorand extruder assemblies supported on portions of the modular frame, withFIG. 4A showing the injector assembly in a raised position and FIG. 4Bshowing the injector assembly in a lowered position where the nozzleassembly would engage a mold;

FIG. 5 is a side view of the assemblies shown in FIG. 4A;

FIG. 6 is a top view of the assemblies shown in FIG. 5;

FIG. 7 is a cut away side view of the assemblies taken along the line7-7 in FIG. 6;

FIG. 8 is a partial detail view of the portion circled at thedesignation 8 in FIG. 7;

FIG. 9A is a partial cut away view of the assemblies taken along theline 9-9 in FIG. 6 and with the rotary check valve shown in extrudeposition;

FIG. 9B is a partial cut away view of the assemblies taken along theline 9-9 in FIG. 6 with the rotary check valve shown in inject position;

FIG. 10 is a partial external perspective view of the extruder assemblyof the apparatus of the present application;

FIG. 11 is a partial external perspective view of the injector assemblyof the apparatus of the present application;

FIG. 12A is a partial external perspective rear view of the rotary checkvalve assembly, and

FIG. 12B is a partial external perspective front view of the rotarycheck valve assembly;

FIG. 13 is a cut away view of the rotary check valve assembly takenalong the line 13-13 in FIG. 12A;

FIG. 14 is a cut away view of the rotary check valve assembly takenalong the line 14-14 in FIG. 12B;

FIG. 15 is a partial perspective view of the rotary or rotating table ofthe present application;

FIG. 16 is a cut away view of the rotary table taken along the line16-16 of FIG. 15;

FIG. 17 is a schematic front perspective view of a clamping assembly ofthe present application which is supported at multiple stationssurrounding the rotary table;

FIG. 18 is a schematic rear perspective view of a clamping assembly ofthe present application;

FIG. 19 is schematic cut away side view of the robotic assembly and themold servicer assembly mounted on a corner of the modular frame of therotary injection molding apparatus of the present application for use atan optional adjacent rotary injection molding apparatus illustratedschematically;

FIG. 20A is a schematic partial bottom perspective view of the roboticassembly illustrated in FIG. 20 and

FIG. 20B is a schematic partial side view of the robotic assembly ofFIG. 20;

FIG. 21A is a schematic perspective view of a preferred embodiment of amulti-section single cavity mold of the type used in the rotaryinjection molding apparatus of the present application;

FIG. 21B is a partial cut away side view taken along the line 21B-21B ofthe mold in FIG. 21A;

FIG. 22 is a schematic perspective view of the mold servicer assemblyillustrated in FIG. 19 and shown in an open position for disassembling amold;

FIG. 23 is a schematic perspective view of the mold servicer assemblyillustrated in a closed position in which a mold is supported in anassembled position;

FIG. 24 is a schematic partial cut away view of the mold servicerassembly taken along the line 24-24 of FIG. 22;

FIG. 25 is a schematic partial cut away view of the mold servicerassembly taken along the line 25-25 of FIG. 23;

FIG. 26 is a schematic partial cut away view of the mold servicerassembly taken along the line 26-26 of FIG. 22;

FIG. 27 is a schematic partial cut away view of the mold servicerassembly taken along the line 27-27 of FIG. 23;

FIG. 28 is a schematic partial perspective view of the robotic gripperassembly illustrated supported on the mold servicer assembly in FIG. 23;

FIG. 29 is a partial, schematic perspective front view of the modularframe supporting partially illustrated elements of the hydraulic,environmental and electrical control systems of the present application;

FIG. 30 is a partial, schematic perspective rear view of the modularframe supporting partially illustrated elements of the hydraulic,environmental and electrical control systems of the present application;

FIG. 31 is a partial, schematic perspective rear view of the modularframe supporting partially illustrated elements of FIG. 30, but withsafety panels removed and cabinet doors opened;

FIG. 32 is a schematic perspective view of a portion of the assemblycontrol system regulating certain of the environmental, electrical andvalving systems of the present application; and

FIG. 33 is a schematic cut away side view of the assembly control systemtaken along the line 33-33 of FIG. 32.

DETAILED DESCRIPTION OF THE DRAWINGS

Turning now to the illustrations of the present embodiment, a multistation rotary injection molding apparatus 10 provides high productioninjection molding of manufactured products M. In the illustratedembodiment, the rotary injection molding apparatus 10 is supported on amodular frame 20 and includes a rotating table 22 having 10 workstations 24 positioned along the periphery of the rotating table 22.Independent clamp assemblies 28 are supported on the rotating table forengagement with a single extruder and injector assembly, also supportedon the modular frame 20. In the preferred embodiment of the apparatus,cure times for manufactured products M are between approximately 75 to160 seconds per product, and preferably approximately 80 seconds perproduct. With small multi-section single cavity molds 30, cycle timesfor movement between positions or stations may be 20 to 30 seconds.

All press operations are automatic and controlled by an Allen Bradleyprogrammable logic controller, such as an SLC 5/05 PLC. Additionally,the apparatus is programmed using Allen Bradley RS Logix 500 software,as well as a variety of other Allen Bradley system controllers, forexample, for remote scanner modules in communication with the rotatingtable (1747-SN), servo controllers (1398 Ultra AC), drives for motorspeed control, IEC style pushbutton switches, and guard master safetyrelays and emergency stop buttons, as well as other conventionalcontrollers all of which are well known to one of ordinary skill in theart and are collectively referred to herein as the central controlsystem 54. Operation of these numerous controller, drive, sensor andswitch components are provided at an operator interface terminal, suchas a Parker Automation CTC PS10 color touch screen 56 which isillustrated in FIG. 1 on a control arm which enables the terminal toclear all equipment and secondary equipment.

Certain of the environmental, electrical and valve systems are providedwithin a central cabinet 58 located within the modular frame 20 as shownin FIGS. 29, 32 and 33. Air intake and exhaust are provided from thecentral cabinet via a rotary air union to provide air cooling for thecontrol components. The improved cabinet 58 is fully insulated andincludes 3 insulated doors upon which electrical components may bemounted, and which also enable ready access to the controls for repairand cleaning. Additional system units, such as the Rexroth hydraulicunit 59 with dual smart pumps, are also secured to the modular frame,and preferably at corner locations such that ready access to the unitsis provided upon removal of the adjacent doors or safety panels 20 f, asshown in FIG. 29. Likewise, electrical connections are provided adjacentframe openings and connections are preferably quick disconnectcomponents to permit quick change out of components.

In the illustrated embodiments of FIGS. 1 through 7, 15-16 and 29 to 31elements of the modular frame 20 are illustrated. For example, the framesupports each of the apparatus components on a machined base plate 20 aand their positions are registered with respect to each of the othercomponents. Fork lift openings 20 b are provided to enable convenientmovement of the apparatus from one location to another and for shipment.Additional attachment openings 20 c are provided to enable attachment ofadditional upstream or downstream processing stations PS of the typeillustrated in FIG. 2, such as intake and take away conveyors, swaggers,carousels, bowl feeders, quality control vision checks, as well as othernecessary processing options. The open structure of the modular framealso enables the use of storage drawers 20 h of the type shown in FIG.29 through 31, which provide ready access to the electrical systems,temperature and air regulators which may be supported therein.

As shown in FIG. 15, additional components, such as a rotating tableplatform 20 d, are secured to the base plate 20 a using conventionalfasteners. Grooves 20 e are provided to ensure proper positioning orregistration between the apparatus components. The rotating tableplatform grooves 20 e are engaged by frame sidewalls 20 g which supportadditional apparatus components. The use of the modular frame of thepresent invention provides the apparatus with a small plant floorfootprint, many space saving aspects, as well as the ability to surroundthe apparatus with safety panels 20 f for operator protection.

The injection molding apparatus modular frame 20 supports a fixedinjection molding operation station 40 which includes an extruderassembly 46, and an injection assembly 48 with a nozzle assembly50,which are interconnected at a rotary check valve assembly 52.

As show in FIG. 6, the frame side walls 20 g supporting the injector andextruder assemblies are of different thickness. The side walls arepreferably aluminum castings to support the necessary pressures providedto the mold 30 at the injection molding operation station 40. Additionalstrengthening ribs or cross bracing 20 i are provided between thesidewalls to resist twisting movement and ensure support of theassemblies at the station 40.

Elastomeric stock material is supplied to the extruder assembly througha door adjacent the extruder assembly by a supply assembly (notillustrated). The extruder assembly is designed with all bolt fasteners88 on one end, which extend to enable the use of larger rods, whichimproves wear resistance in the internal seals and permits the use ofhigher extrusion pressures. The material is plasticized by the rotatingextruder screw 94 using a hydraulic motor 86. The extruder is providedwith a heated jacket to maintain material temperatures at the presetdesired temperature for proper curing of the material. A precise amountof desired and predetermined material is then fed through a mechanicalrotary check valve assembly 44 to the injector assembly 48.

The rotary check valve assembly 44 is also mounted between cast aluminumsidewalls 20 g, which are engaged along mating rails with the sidewallsof the injection molding operation station as shown in FIG. 6. Ahydraulic unit 90 which rotates the check valve assembly is likewiselocated within a cast housing 91 to support the assembly for highpressure operation. The use of a stronger housing resists movement ofthe assembly 44 during operation which provides more accurate operation.The interior portion of the sidewalls adjacent the injector assembly isprovided with insulation material 92. When in the position illustratedin FIG. 9A, the rotary check valve 100 provides a material flow path tothe injector assembly 48. When the injection chamber 110 of the injectorassembly is filled to the proper amount, the rotary check valve 100 ismoved to the position shown in FIG. 9B by the hydraulic unit, and a flowpath is provided for the material to be injected into a mold 30 via anozzle assembly 50. In the event it is necessary to remove material fromthe extruder or injector assemblies, removal of the bolt 102 from therotary check valve assembly 44 enables materials within either assemblyto be readily removed. The rotary check valve 100 is preferably a steelvalve with an Armalloy® coated bronze sleeve. Additionally, as shown inFIG. 13, the rotary check valve is maintained within the assembly 44 bya bolt 102′. By removing the bolt 102′ the entire valve 100 may bereadily removed from the assembly. Alternatively, the opening providedfor bolt 102′ could be provided with a temperature sensor or othercontrol device, as the system may require.

The central structure of the injector assembly 48 is preferablyillustrated machined of round bar stock 113 with an opening forproviding access to the assembly 48 for cleaning and changing of wornparts. The assembly includes a heated thermal jacket 111 to maintainmaterial temperatures. The hydraulic unit 112 and heated jacket 111 areinterconnected with the intermediate bar stock 113 via four tie rods asshown in FIG. 11. FIGS. 9A and 9B illustrate that the injector assemblyplunger tip 114 is provided with a Teflon® bronze seal, which togetherwith the injection pressure provided during the injection operation,form surrounding seals which prevent material from moving backward inthe injection chamber and thereby reduces wear. Additionally a chamferedopening or lead in 108 is provided into the injection chamber 110. Thecombination of the lead in 108 with the aligned sealed tip functions tokeep the plunger aligned and also reduces plunger tip wear.

Before injection of the mold 30 with elastomeric material begins, themold servicer assembly 42 disassembles the multi-section single cavitymold 30 at the disassembly station 43. The mold servicer assembly 42 anddisassembly station 43 are shown in FIG. 19 supported adjacent theinjection molding station 40 and a robotic arm assembly 70.

The preferred multi-section single cavity mold to be supplied to themold servicer assembly 42 is illustrated in FIGS. 21A and 21B. The moldis a three part or section mold with top, middle and bottom sections 32,33 and 34, respectively. However, two, four or more mold sections may bedesired. The external surface of the mold 30 is preferably provided with1\4 inch aircraft insulation. A round body design is also preferred.Each section is provided with mounting structure or rails 60 for beingsupported within the mold servicer assembly 42, and a side rail 6 o′ isalso provided for movement of the middle mold section 33. A sprueopening 38 engages the nozzle assembly 50 during injection, and the moldmaterial is provided to the mold cavity 62 via sprue channels 36. In theillustrated embodiment the top plate 32 is effectively a removable sprueplate which enables access to the sprue opening 38 and channel 36 formore reliable removal of waste sprue material with the top plate 32.Inserts W or other product components are supplied to the mold cavity 62by the robotic arm assembly 70.

The robotic assembly or robot arm 70 is also supported on the modularframe 20. The robotic assembly illustrated is an Adept six axis robot.The robot arm preferably includes 6 degrees of freedom to provide moreversatility of functionality and to reduce cycle time. The robot arm issupported on the frame 20 by an aluminum cast plate 72. The plate 72 isprovided offset from the modular frame 20 to allow greater range ofmotion, and is also positioned at a corner of the frame 20 to permitoptional access to additional adjacent injection molding systems 10′, asshown in FIG. 19. The robot arm 70 may be positioned in either aconventional configuration, or in an inverted mounting configuration asshown in the figures. A Robohand quick change robot end 74 is providedfor engagement with product inserts or components W and finishedproducts M.

The mold servicer assembly 42 first receives the mold 30 in an assembledcondition when the mold servicer assembly 42 is in a closedconfiguration as shown in FIG. 23. In this position the mold top section32 is engaged along its mating rails 60 within grooves or guide bars 81in an upper mold assembly 76. The mold middle section 33 is engagedalong its mating rails 60 within guide bars 81 in a center mold assembly77. The mold bottom section 34 is engaged along its mating rails withinguide bars 81 in a lower mold assembly 78. Each of the upper, center andlower mold assemblies 76, 77, 78 of the mold servicer assembly isprovided with a hydraulic cylinder unit 82 for movement of itsrespective mold section. Each of the hydraulic units 82 preferablyincludes a Temposonics position sensor to provide true positioninformation to the system controller 54 and thereby obtain morecontrolled motion of the assemblies, such as variable speed. Thehydraulic cylinder units 82 are provided so that they can beindividually removed from the mold servicer assembly 42 while it isfully assembled. Additionally, each of the guide bars 81 are removablefrom their respective assemblies for providing alternative split moldoptions.

Once the mold 30 is positioned within the mold servicer assembly 44, thehydraulic cylinder units of the upper and lower assemblies operate todisassemble the mold by vertically moving and rotate the top and bottommold sections, respectively, to the locations shown in FIG. 22. Theupper assembly 76 is moved vertically upward to a position where a spruepicker assembly 120 (shown in FIG. 28) having a Robohand gripper 122providing several degrees of freedom of movement, may access a sprueopening 28 in the mold top section 32 to remove any waste materialremaining in the mold from a prior molding operation. An integratedrotary mechanism 121 turns with the upper mold assembly 76. To removeany manufactured products M from the bottom mold section 34 within thelower mold assembly 78, the assembly may rotate down upon a pin whichwould raise the product M within the bottom mold section 34 and enablethe robotic arm 70 to readily gain access to the product.

The center mold assembly 77 does not rotate but moves horizontally usingthe hydraulic unit 82 for an appropriate distance for any necessarymiddle mold section 33 adjustments. A high powered magnet 124 isprovided adjacent the guide bars 81 for maintaining mold sections withinthe guide plates 81 during rotating movement of the mold servicerassembly 42. Rotating movement during the vertical lifting and loweringof the upper and lower mold assemblies, 75, 78 is assisted with thickwall guide cams 126 along the central axis of the mold servicer assembly42. having

Once any sprue waste and manufactured products are removed from thedisassembled mold sections 32, 33, 34, the mold sections may bereassembled by return movement of the mold servicer assembly 42 to theposition shown in FIG. 23.

The assembled mold 30 is pushed out of the center mold assembly 77 usingthe horizontal movement of the center mold assembly 77. The mold 30 ispushed into a clamping assembly 28 which is mounted at a work station 24on the rotary table 22. The upper and lower clamping assembly posts 128are engaged through spaced openings 129 in the rotary table 22. Theposts 128 are joined on top of the rotary table at an upper bridge 132and under the rotary table 22 at a lower bridge 132′. The posts arejoined together adjacent the openings 129 at guide bushings 134. Themounting of clamping assemblies 28 at each work station 24 surroundingthe periphery of the rotating table 22 is best seen in FIG. 3. The mold30 is received into an opening 130 in the clamping assembly 28 whichaccommodates a mold 30 of approximately 8 inches in height asillustrated in FIG. 17 and using integrated mold guides 136. The mold 30is engaged on the bottom mold section 32 with a bronze wear plate 138.Upper and lower heated platens 140 are adjacent the mold sections,followed by an inch of insulation material 142 as well as a heater wirecover. A heavy duty hydraulic cylinder 144 is provided for clamping themold 30 within the clamping assembly during the injection operation atthe injection molding operation station 40 and for applying thenecessary clamping pressure during curing of the product M as the mold30 is rotated within the clamping assembly 28 around the work stations24 at the rotary table 22. The rotary table 22 rotates using an AllenBradley servo drive motor 146, with an attached gear reducer 148 engagedwith gear teeth 150 secured to the bottom of the rotary table 22.

Once engaged within the clamping assembly 28 and clamped, the rotatingtable 22 then indexes the mold 30 to the injection molding operationstation 40 adjacent the extruder and injector assemblies 46, 48. Oncethe nozzle assembly 50 is lowered into engagement with the sprue opening38 in the mold, the material is injected into the mold via the extruder,injector and rotary check valve assemblies. A supplemental nozzle touchsystem 51 has been designed to assist the nozzle assembly 50 so that itmay be retracted back from the heated platen to prevent curing of thematerial inside the nozzle assembly, to provide clearance when therotary table 22 indexes and to provide access to change out the nozzle.

Once the rotary table 22 has indexed the clamped mold to each of the 10preferred work stations 24, the mold 30 is returned to the mold servicerassembly 42 and is disassembled to again initiate the molding cyclewithin the mold. It should be understood that the rotary injectionmolding apparatus of the present application enables continuoussynchronous molding of the single cavity molds 30 within each of workstations 24 and the disassembly station. 43.

While an exemplary embodiment of the rotary injection molding apparatusand its method of use having been described with a degree ofparticularity, it is the intent that the apparatus include allmodifications and alterations from the disclosed design falling withinthe spirit or scope of the appended claims.

1. An injection molding apparatus for manufacturing products containingelastomeric material within single cavity molds, said apparatuscomprising, a modular frame supporting an injection molding operationstation including an injector assembly having a pressure sensitivenozzle assembly, the injector assembly engaged with an extruder assemblyat a check valve assembly, and a mold servicer assembly for assembly anddisassembly of single cavity molds, a robotic assembly positioned forinserting and removing products or product components from positionswithin said injection molding apparatus; and a rotating table having aplurality of positions along the periphery of the rotating table to movea single cavity mold into and out of engagement with the injectionmolding operation station, each position supporting a clamping assemblyfor clamping a single cavity mold.
 2. The injection molding apparatus ofclaim 1 wherein the rotating table has a substantially circularconfiguration.
 3. The injection molding apparatus of claim 2 whereinoperation of the injector assembly, nozzle assembly, extruder assembly,robotic assembly, rotating table and clamping assemblies are allcomputer controlled by a central programmable controller.
 4. Theinjection molding apparatus of claim 1 wherein the robotic assembly ispositioned at a corner of the modular frame to permit use of the roboticassembly at one or more adjacent injection molding systems.
 5. Theinjection molding apparatus of claim 1 wherein the modular frameincludes sidewalls which are aluminum castings.
 6. The injection moldingapparatus of claim 1 wherein said injector assembly and extruderassembly are configured to enable injection pressures sufficient toinitiate curing of the product.
 7. The injection molding apparatus ofclaim 1 wherein said mold servicer assembly includes a bronze centraldrive cam for improved wear resistance.
 8. A method for manufacturingproducts containing elastomeric materials using an injection moldingsystem, comprising the steps of: disassembling a multi-section singlecavity mold at a disassembly station to reveal a mold cavity andinserting any inserts to be molded into a manufactured product into themold cavity; reassembling the multi-section single cavity mold andproviding the assembled mold to a clamping assembly supported on arotating table having a plurality of positions along the periphery ofthe rotating table, said clamping assembly maintaining the single cavitymold under pressure; rotating the rotating table to move the singlecavity mold into engagement with an injection molding operation station,the station including an injector assembly having a pressure sensitivenozzle assembly, the injector assembly engaged with an extruder assemblyat a check valve assembly; positioning the nozzle assembly of theinjector assembly against the single cavity mold and injectingelastomeric material from the extruder assembly; removing the nozzleassembly from engagement with the single cavity mold; rotating thesingle cavity mold supported within the clamping assembly out ofengagement with the injection molding operation station and around therotating table during curing of the product, to the disassembly station;and disassembling the single cavity mold at the disassembly station andremoving the cured product from the single cavity mold.
 9. The method ofclaim 8 further comprising the step of synchronizing operations at eachof the stations and positions to provide in-line manufacture or cure ofproducts within each of the clamping assemblies positioned on therotating table.
 10. The method of claim 8 further comprising the step ofremoving the cured product from the injection molding apparatus using abelt conveyor positioned adjacent the mold disassembly and assemblyposition.
 11. The method of claim 8 further comprising the step ofproviding the cured product to other product finishing operations. 12.The method of claim 9 further comprising the step of maintaining thesingle cavity mold under pressure sufficient to cure the product withinthe clamping assembly.
 13. The method of claim 9 further comprising thestep of providing the product inserts to the cavity of the single cavitymold using a robotic assembly positioned on a corner of the modularframe.
 14. The method of claim 8 wherein curing the product within themulti-section single cavity mold rotating around the rotating tablefollowing engagement with the injection molding operation station untilthe disassembly station is reached ranges from a time of approximately80 to 160 seconds.
 15. The method of claim 8 wherein the step ofrotating the rotating table provides synchronized movement of andoperations on the multi-section single cavity molds at each of theplurality of positions along the periphery of the rotating table. 16.The apparatus of claim 1 wherein the injector assembly and the extruderassembly are supported at an angle of between 20 and 25 degrees withrespect to a central axis between sidewalls of the modular frame.